Shrinkproofing keratinic textile materials through reaction with polyisocyanates in conjunction with active hydrogen containing compounds

ABSTRACT

KERATINIC FIBERS ARE MODIFIED WITH POLYISOCYANATES IN CONJUNCTION WITH POLYFUNCTIONAL COREACTANTS TO IMPROVE THE SHRINK RESISTANCE, DYEABILITY AND SETTABILITY THEREOF AND UNIFORM OR BLENDED TEXTILE STRUCTURES MADE THEREFROM.

United States Patent U.S. Cl. 8-127.6 9 Claims ABSTRACT OF THE DISCLOSURE Keratinic fibers are modified with polyisocyanates in conjunction with polyfunctional coreactants to improve the shrink resistance, dyeability and settability thereof and uniform or blended textile structures made therefrom.

This invention relates to a process for modifying the characteristics of structures containing keratin fibers and, more particularly, to processes for reducing the relaxation and felting shrinkage of a structure containing keratin fibers and for setting said fibers in a given configuration if desired, and and to the structures so improved.

This application is a continuation-in-part of my copending U.S. patent application, Ser. No. 230,712, Oct. 15, 1962, now abandoned.

The relaxation and felting shrinkages of structures containing keratin fibers have been a serious problem in the textile industry. The considerable amount of research and development has resulted in several methods that will inhibit the felting shrinkage of these structures. No method, however, has been developed prior to this invention for the control of relaxation shrinkage. The most widely used process to date involves digestion of the fiber scales by chlorination. A similar effect is obtained by use of acid/ permanganate. Both of these methods, however, are objectionable because of the loss of tensile strength and abrasion resistance which results from degradation of the fibers. Furthermore, fabrics treated by these methods must be made to higher weights so that after the degradative action, sufficient strength remains in the structure to meet minimum wear requirement. The combination of degradation plus weight loss during the processing results in the necessity for using more wool and, therefore, a higher cost of product.

A considerable amount of research has been conducted to circumvent the degradative action of chlorination and other oxidative methods. This research has produced several procedures which are not as Widely used at the present time. One method consists of depositing on the surface of the keratin fiber a polymeric material as, for example, a polyamide-type polymer. In this method, the fabric is passed through a solution of a diamine and then treated with a salt of a dibasic acid; the polyamide is thus formed at the interface between the diamine and the salt of the dibasic acid to form a coating on the fiber.

While adequate shrinkproofing is effected in this manner, there are several objectionable features to this process. In the first place, dye migration caused by the affected. The relaxation shrinkage is not adequately inhibited.

Other polymeric resins designed to form a film on the keratin fibers have also been developed. Combinations of polyamides with epoxys and/or acrylates have been used; also polyesters which have been made to high molecular weight to obtain flexibility have been used in conjunction with peroxide curing agents. These processes also produce fabrics which have a harsh hand and poor drape when the amounts of these modifying materials are such as to inhibit the shrinkage to the required amount. The relaxation shrinkage is also not adequately inhibited.

Another process has been developed for inhibiting the shrinkage of structures containing keratin fibers by use of isocyanates. To obtain sufficient reaction, using isocyanates alone, to render the fabric being treated resistant to shrinkage, long refluxing conditions are required, which makes this process commercially impracticable. Furthermore, to obtain the desired resistance to shrinkage, large amounts of the isocyanate compounds must be added to the fibers which results in a fabric that is both harsh and stiff, having a hand more like horsehair than wool.

Relaxation and felting shrinkage propensities are not the only problems associated with fabrics containing keratin fibers. Such fabrics, particularly those containing at least a major proportion of keratin fibers, are also characterized by a low degree of configurational stability. For example, the crease in a pair of wool trousers is virtually eliminated by wetting. The same is true of the lustrous finish applied to wool fabrics in a typical textile finishing operation.

To overcome these difliculties durable configurations have been imparted to such fabrics through the use of reducing agents. According to these prior art processes, the fabric is impregnated with the reducing agent, whereupon some of the cystine disulfide linkages of the keratin fiber molecule are ruptured. The resulting fabric, in a reduced condition, can be heat pressed, generally in the presence of large quantities of moisture, into configurations which are durable to subsequent wetting. These procedures, particularly as improved by the addition of certain compounds which obviate the use of large quantities of moisture during pressing, have been highly successful because of the desirable properties imported to fabrics so-treated. H

The processes, however, are degradative processes and, therefore, the physical properties of the resulting fabrics are diminished. Furthermore, the reduced keratin fibers have a characteristic, unpleasant odor regardless of the reducing agent utilized. Additives have been developed for eliminating this odor, but such techniques invariably increase the cost of the process.

Although present processes for setting keratin fibers in durable configurations have been developed to practicable levels, it would be highly desirable if a process could be developed which enhanced, rather than degraded, physical properties and which avoided the unpleasant odor of reduced 'keratin fibers without the use of costly additives. Even more desirable would be a process which resolved these problems while providing a fabric, treated at the mill level, which is presensitized for subsequent durable setting, by the garment manufacturer, in the absence of large quantities of water.

The difficulties associated with the above prior art processes are overcome in accordance with the process of this invention which comprises reacting the keratin fibers with a polyfunctional isocyanate in combination with a monomeric polyfunctional compound selected from polyols, acids, sulfhydryl compounds, and mixtures thereof. To set the fibers in a given configuration, it is required only that the fibers be maintained in the desired configuration during this reaction.

The process of this invention requires the use of relatively small amounts of material to obtain the required stabilization and/ or settability. The process of application is a simple one involving impregnating the keratin fibers by any conventional technique such as padding, immersing, spraying or the like, followed by drying and curing of the components on the fibers. These steps may be run intandem on equipment that is available in textile plants.

The products of this invention not only are superior in almost every instance to those treated by other known methods but also are superior to the same fabric prior to treatment. In the process of this invention there is no degradative action on the wool fiber; on the contrary, improvements in strengths and abrasion resistance are obtained over the untreated controls. It has also been found that more uniform dyeing may be accomplished on keratin fibers treated in accordance with this invention than those treated by the degradative processes of the prior art.

A particular advantage in the practice of this invention is the virtual elimination of the relaxation shrinkage of the fabric, which is a highly desirable property in that it is not necessary that the fabric be preshrunk prior to cutting into garments as is required in the processes of the prior art. This results in savings of both labor and material since yardage is always lost when the fabric is relaxed prior to cutting into garments.

The process also allows the manufacture of lighter weight garments which are Washable without felting shrinkage which has not been possible in processes of prior art. Besides the savings in wool, it is often highly desirable to have lighter weight fabrics available for the production of more comfortable garments.

The hand of fabrics treated in accordance with this invention may be varied by balancing construction of the fabric with the amount of pickup of treating compound used in the system.

Although some improvement is noted when the polyfunctional isocyanate and monomeric polyfunctional compounds are present in amounts sufficient to provide a ratio of N=C=X, wherein X is oxygen or sulfur, to total active hydrogen atoms of at least about 0.4, best results are obtained at higher ratios, for example, greater than about 1. Shrinkage inhibition and settability at commercial levels is obtained with less reactants at higher ratios of N=C=X to total active hydrogen atoms. The presence of active hydrogen atoms may be determined by the Zerewitinoff method. (Zerewitinofl, Ber., 40, 2023 (1907); Ber., 41, 2236 (1908); Kohler, J. Am. Chem. Soc., 49, 3181 (1927).

In the practice of this embodiment of the invention, it is preferred to react the polyfunctional isocyanate and monomeric polyfunctional compound of the desired type with the keratin fibers in the presence of catalyst. Any of the well-known catalysts for the reaction of active hydro gen atoms with isocyanates may be used. Of these catalysts, which are used in the production of polyurethanes, the organo-tin compounds are preferred, particularly stannous octoate.

Among the classes of catalysts which can be used, there are included the inorganic and organic bases such as sodium hydroxide, sodium phenolate, tertiary amines and phosphines. Particularly suitable amine catalysts include 2,2,l-diazabicyclo-octane, trimethylamine, 1,2-dimethylimidazole, triethylamine, diethyl cyclohexylamine, dimethyl long-chain C to C amines, dimethylaminoethanol, diethylaminoethanol, N-methyl morpholine, N- ethyl morpholine, triethanolamine and the like. Other suitable catalysts include arsenic trichloride, antimony trichloride, antimony pentachloride, antimony tributoxide, bismuth trichloride, titanium tetrachloride, bis(cyclopentadienyl) titanium difluoride, titanium chelates such as octylene glycol titanate, dioctyl lead dichloride, dioctyl lead diacetate, dioctyl lead oxide, trioctyl lead chloride, trioctyl lead hydroxide, trioctyl lead acetate, copper chelates such as copper acetylacetonate, and mercury salts.

Organo-tin compounds characterized by at least one direct carbon to tin valence bond are also suitable as catalysts.

Among the many types of tin compounds having carbon to tin bonds, of which specific representative compounds have been tested and shown to be active, are tin compounds having the general formulae set forth as follows:

in which the Rs represent hydrocarbon or substituted hydrocarbon radicals such as alkyl, aralkyl, aryl, alkaryl, alkoxy, cycloalkyl, alkenyl, cycloalkenyl, and analogous substituted hydrocarbon radicals, the Rs represents hydrocarbon or substituted hydrocarbon radicals such as those designated by the Rs or hydrogen or metal ions, the Xs represent hydrogen, halogen, hydroxyl, amino alkoxy, substituted alkoxy, acyloxy, substituted acyloxy, acyl radicals or organic residues connected to tin through a sulfide link and the Ys represent chalcogens including oxygen and sulfur.

Among the compounds of group (a) that deserve special mention are trimethyltin hydroxide, tributyltin hydroxide, trimethyltin chloride, trimethyltin bromide, tributyltin chloride, trioctyltin chloride, tripheuyltin chloride, tributyltin hydride, tripheuyltin hydride, triallyltin chloride, and tributyltin fluoride.

The compounds in group (b) that deserve particular mention and are representative of the group include dimethyltin diacetate, diethyltin diacetate, dibutyltin diacetate, dioctyltin diacetate, diluaryltin diacetate, dibutyltin dilaurate, dibutyltin maleate, dimethyltin dichloride, dibutyltin dichloride, dioctyltin dichloride, diphenyltin dichloride, diallyltin dibromide, diallyltin diiodide, bis (carboethoxymethyl)-tin diiodide, dibutyltin dimethoxide, dibutyltin dibutoxide,

(in which x is a positive integer), dibutyl-bis[O-acetylacetonyl]-tin, dibutyltin-bis(thiododecoxide), and

wmnmscmcorsOon all readily prepared by hydrolysis of the corresponding dihalides. Many commercially available compounds used as stabilizers for vinyl resins are also included in this group.

Among the compound that are representative of group (0) are butyltin trichloride, octyltin trichloride, butyltin triacetate and octyltin tris(thiobutoxide).

Typical among the compounds of group ((1) are dimethyltin oxide, diethyltin oxide, dibutyltin oxide, dioctyltin oxide, diluaryltin oxide, diallyltin oxide, diphenyltin oxide, dibutyltin sulfide, [HOOC(CH SnO,

(CH2OCH2)X 1CH2] ZSIIO and 3 2 z z) x-1 2 H 5] RO (in which the xs are positive integers).

Methylstannonic acid, ethylstannonic acid, butylstannonic acid, octylstannonic acid, HOOC(CH SnOOH.

and

CHgOCH CHgOOHz CH2O 5SI1OOH are examples of group (e) catalysts and group (1?) catalysts are represented by HOOSn(CH SnOOH and HOOSnCH (CH OCH CH SnOOH the xs being positive integers.

Typical compounds in group (g) include compounds as poly (dialkytin oxides) such as dibutyltin basic laurate and dibutyltin basic hexoxide.

Other compounds that are efficient catalysts are those of group (b), of which the organo-tin compounds used as heat and light stabilizers for chlorinated polymers and available under the trade names Advastab 17-M (a dibutyl tin compound believed to contain two sulfur-containing ester groups), Advastab T-SO-LT (a dibutyl tin compound believed to contain two ester groups), are typical, as well as many other organo-tin compounds available under such trade names as Advastab, Nuostabe and Thermolite.

Suitable polyols or polyhydroxy compounds, for use in accordance with this invention include ethylene glycol,

propylene glycol,

trimethylene glycol, 1,2-butylene glycol,

1,3-butane diol,

1,4butane diol,

1,5-pentane diol,

1,2-hexylene glycol, 1,10-decane diol, 1,2-cyclohexane diol, 2-butene-1,4 diol, 3-cyclohexene-1,l-dimethanol, 4-methyl-3-cyclohexene,1,1-dimethanol, 3-methylene-1 ,5 -pentanediol, 3,2-hydroxyethyl cyclohexanol, 2,9-para-methanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,5-dimethyl-2,5-hexane diol and the like; alkylene oxide modified diols such as diethylene glycol,

(2- hydroxyethoxy -1-propanol,

4- (Z-hydroxyethoxy)-1-butanol,

5- (2-hydroxyethoxy) -1pentanol, 3- (Z-hydroxypropoxy) l-propanol, 4- (2-hydroxypropoxy) -1-butanol, 5- (Z-hydroxypropoxy)-1-pentanol, 1- (2-hydroxyethoxy) -2butanol,

1- (Z-hydroxyethoxy) -2-pentanol, 1- (2-hy'd roxymethoxy) -2-hexanol, 1- (Z-hydroxyethoxy) -2-octanol,

and the like.

Representative examples of ethylenically unsaturated low molecular weight polyols include 3 -allyloxy- 1 5 -pentanedio1;

3-a1lyloxy-1,2-propanediol; 2-allyloxymethyl-Z-methyl-l,3-pr0panedi0l; 2-methyl2- (4-pentenyloxy methyl] -1,3-propanediol; and 3-(o-propenylphenoxy)-1,2-propanediol.

Representative examples of low molecular weight polyols having at least 3 hydroxyl groups include: glycerol; 1, 2,6-hexanetriol; l,1,1-trimethylolpropane; 1,l,1,-trimethylolethane; pentaerythritol; 3-(2-hydroxyethoxy)-1,2-propanediol; 3 (2 hydroxypropoxy) 1,2 propanediol; 6 (2 hydroxypropoxy) 1,2 hexanediol; 2 (2 hydroxyethoxy)-1,2hexanediol; 6-(2-hydroxypropoxy) 1, 2 hexanediol; 2,4-dimethyl-2-(2-hydroxyethoxy)methylpentanediol1,5:mannitol; glactitol; talitol; iditol; allitol; altritol; guilitol; arabitol; ribitol; xylitol; erythritol; threitol; 1,2,5,6-tetrahydroxyhexane; meso-inositol; sucrose; glucose; galactose; mannose; fructose; xylose; arabinose; dihydroxyacetone; glucose-a-methylglucoside; 1,1,1-tris [(2-hydroxyethoxy)methyl]ethane and l,l,l-tr,is[(2-hydroxypropoxy methyl] propane.

There may also be utilized low molecular weight polyalkyleneether glycols such as tetraethyleneether glycol, triethyleneether glycol, tritetramethyleneether glycol, ditetramethyleneether glycol and the like.

Exemplary diphenylol compounds include 2,2-bis(p-hydroxyphenyl)propane; bis(p-hydroxyphenylmethane and the various diphenols and diphenylol methanes disclosed in US. Pats. 2,506,486 and 2,744,882, respectively.

Exemplary triphenylol compounds which can be employed include the alpha, alpha, omega, tris(hydroxypenyl)alkanes such as 1, 1,3 -tris (hydroxyphenyl ethane;

1,1, 3-tris (hydroxyphenyl propane;

1, 1 ,3-tris (hydroxy-3-methylphenyl propane;

1, 1 ,3-tris (dihydroxy-3-methylphenyl) propane; 1, 1,3-tris (hydroxy-2,4-dimethylphenyl) propane; 1, 1,3-tris (hydroxy-2,S-dirnethy-lphenyl) propane; 1, 1 ,3-tris (hydroxy-2,6-dimethy1phenyl) propane; 1, 1 ,4-tris (hydroxyphenyl) butane;

1, 1,4-tris (hydroxyphenyl) -2-ethylbutane;

1, 1,4-tris (dihydroxyphenyl) butane; 1,1,5-tris(hydroxyphenyl)-3-methylpentane; 1,1,8-tris(hydroxyphenyl)-octane;

1,1-10-tris (hydroxyphenyl)decane;

and such corresponding compounds which contain substituent groups in the hydrocarbon chain, such as 1,1,3-tris(hydroxyphenyl)-2-chloropropane; 1, 1 ,3-tris (hydroxy-3 -propylphenyl) -2-nitropropane; 1,1,4-tris(hydroxy-3-decylphenyl)-2,3-dibromobutane;

and the like.

Tetraphenylol compounds which can be used in this invention include the alpha, alpha, omega, omega, tetrakis 'hydroxyphenyl)alanes such as 1, 1,2,2-tetrakis(hydroxy-phenyl) ethane;

1,1,3 ,3-tetrakis (hydroxy-3 -methylphenyl propane; 1, 1 ,3,3-tetrakis (dihydroxy-S-methylphenyl) propane; 1, 1,4,4-tetrakis (hydroxyphenyl butane;

1, 1,4,4-tetrakis(hydroxyphenyl)-2ethylbutane; 1,1,5,5-tetrakis(hydrOxyphenyDpentane; 1,1,5,5-tetrakis(hydroxyphenyl)-3-methylpentane;

1, 1, 5 ,5 -tetrakis-( dihydroxyphenyl) pentane; 1,1,8,8-tetrakis(hydroxy-3-butyl-phenyl) octane;

1, 1 ,8,8-tetrakis (dihydroxy-3-butylphenyl) octane;

1, 1 ,8,8-tetrakis (hydroxy-2,S-dimethylphenyl) octane; 1,1,10,lO-tetrakis(hydroxyphenyl)-decane,

and the corresponding compounds which contain substituent groups in the hydrocarbon chain such as 1, 1 ,6,6-tetrakis (hydroxyphenyl -2hydroxyhexane;

1,1,6,6-tetrakis (hydroxyphenyl -2-hydroxy-5-methylhexane;

1, 1,7,7-tetrakis(hydroxyphenyl)-3-hydroxyheptane;

1, 1,3 ,3-tetrakis (hydroxyphenyl -2-nitropropane;

1,1,3 ,3-tetrakis(hydroxyphenyl -2-chloropropane;

1,1,4,4-tetrakis(hydroxyphenyl)-2,3-dibromobutane;

and the like.

Alkanolamines may also be utilized, for example,

ethanolamine, methyldiethanolamine, diethanolamine,

7 triethanolamine, N,N,N,N'-tetrakis(2-hydroxypropyl)ethylene diamine, N-propyl-N,N,N-tri(2-hydroxyethyl) -propylene diamine, N,N-diethanolaniline, tris-hydroxymethylaminomethane, 2-amino-2-methyl-1,3-propane diol, 3-aminopropanol, 4-amino-1-propanol, 6-amino-1-hexanol, l-amino-l-decanol, N,N-di(hydroxyethyl)-m-toluidine, N,N-di (hydroxyethyl) -3 ,5-Xylidine, N,N-di(hydroxyisopropyl)-m-toluidine, N,N-di(hydroxyisopropyl)-2,6-dimethyl aniline,

and the like.

Suitable polyfunctional acids include the aliphatic acids, such as malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, B-methyladipic, 1,2-cyclohexane dicarboxylic, teraconic acid, isatropic acid, citric acid, tartaric acid and the like.

Aromatic acids are also suitable, for example isophthalic, terephthalic, uvitic (5,1,3), uvitonic (2,4,6), salicylacetic, 1,4-naphthalene dicarboxylic, 1,8-naphthalenedicarboxylic, 1,10-diphenic acid, 2,9-diphenic acid, benzophenone dicarboxylic acid, pyrornellitic, mellophanic, trimellitic, trimesic and the like, as are heteroaromatic acids such as pyridine tricarboxylic acid, pyridine dicarboxylic acid and the like.

Suitable polyfunctional sulfhydryl compounds include l,4-butanedithiol, 1,5-pentanedithiol, 1,2-hexanedithiol, ethylene thioglycol, propylene thioglycol, trimethylene thioglycol, 1,10-decane dithiol, 1,2-cyclohexanethiol, 2- butene- 1,4-dithiol, 2,9-para menthanedithiol ethylcyclohexyl dimercaptan, 2,2,4-trimethyl-1,3-pentanedithio, and the like. In this regard, the keratin fibers can be treated with reducing agents to provide reactive sulfhydryl groups in situ.

In most instances, the polyfuncitonal isocyanate and monomeric polyfunctional compound may be applied to the fabric or other structure from a single solution, although, if desired, the components may be applied separately. This latter technique is wholly unnecessary, however, when a non-reactive solvent is utilized.

By non-reactive as used herein is meant a solvent in which reactivity between the polyfunctional isocyanate and the monomeric polyfunctional compounds, even in the presence of catalyst, is substantially inhibited. Small amounts of reactive solvents may be present provided the amount present is sufficiently low as not to precipitate a substantial amount of the components with which it is reactive. In other words, sufiicient components remain reactive with the keratin fibers to provide adequate inhibition of shrinkage and/or settability in the fabric or other structure being treated.

Suitable organic solvents include halogenated hydrocarbons, such as trichloroethylene, methylene chloride perchloroethylene, ethylene dichloride, chloroform and the like; aromatic solvents such as toluene, xylene, benzene, mixed aromatics, such as the Solvesso types and the like, n-butyl acetate, n-hutyl ether, n-butyl phosphate, pdioxane, ethyl oxalate, methyl isobutyl ketone, pyridine, quinolene, N,N-dimethylformamide, N,N-dimethylacetamide, 2,2,4-trimethylpentane and the like. Mixtures of solvents may be used.

The use of a non-reactive organic solvent enables the practioner to combine all desired components in a single solution and reaction therebetween is substantially inhibited, thereby greatly facilitating application of all components, even catalyst, uniformly onto the desired structure in controllable amounts. In the absence of a nonreactive solvent, the combined components and catalysts would react, often quite readily, to produce an insoluble polyurethane type polymer which cannot be conveniently applied to the fabric or other structure uniformly in the 8 amounts desired. This reaction, however, is inhibited when a non-reactive solvent is used and the inhibiting influence substantially continues in the fabric until the solvent is removed by any conventional drying technique. After the solvent is removed, the various components are free to cure on the keratin fibers.

By cure as used herein is meant the reaction of the various components, such as the isocyanate (unblocked or blocked as set forth below) monomeric polyfunctional compound system, with the keratin fibers. It is believed that the components react with the fibers, in that extraction methods fail to remove the components after curing. The mechanism of the reaction with the keratin fibers, however, is not completely understood.

When the isocyanate, monomeric polyfunctional compound and catalyst are mixed without apparent reaction therebetween and applied directly to the keratin fibers, it is not at all understood just how the various components combine witth the keratin fibers to inhibit the shrinkage thereof or to see the fibers in a given configuration. It is not known, for example, whether the components first combine to form an -N=(. X terminated pre-polymer which then reacts with the keratin fiber or Whether the components react individually or sequentially with the various groups in the wool molecule which contain active hydrogen atoms, for example, the amine, hydroxy, thiol, amide guanidine, carboxyl and imido groups.

It is believed, however, that the isocyanate groups present in the isocyanate/polyfunctional monomer system, after driving off the non-reactive solvent and/ or unblocking if required, react with active hydrogen atoms in the wool molecule as follows:

wherein X is as before and R is the residue from the above isocyanates.

The presence of region amounts of water in the structure of keratin fibers will consume free isocyanate groups to lower the N=C'=X to active hydrogen atom ratio of the total system with a consequent increase in felting shrinkage and decrease in settability where the initial ratio is low. This problem may be readily solved by either drying and maintaining dry the said structure during treatment or by compensating for this region moisture by addition of equivalent amounts of isocyanate groups to react with this water. This latter procedure, obviously, is preferred.

Even though the mechanism of curing is not completely known, it is most apparent in the practice of this invention that a very high level of shrinkage inhibition and/ or setting is produced with only very small amounts of isocyanates, either unblocked or blocked as set forth below, when there is combined therewith a monomeric polyfunctional compound as set forth herein.

Exposure of the impregnated fabric or other structure to temperatures above ordinary room temperatures increases the rate of curing. Temperatures from about 220 to about 260 F. are preferred, while temperatures above about 300 F. are considered higher than necessary. Such higher temperatures, however, may be utilized provided care is taken not to expose the keratin fiber to these higher temperatures for so long a time that undue degradation takes place.

The time of curing varies inversely with the temperature utilized. Optimum balance of time and temperature may readily be determined by the practioner of this invention through shrinkage tests or crease ratings.

In the shrinkage inhibition embodiment of this invention, it has been found that the properties of fabrics and other structures treated in accordance with this invention are improved by mechanically working the fibers of the fabric after curing. This is most eflicaciously accomplished during a scouring operation, during which the fabric is passed repeatedly in and out of an aqueous solution containing small amounts of a wetting agent, with periodic squeezing between rolls. Similar effects are noted during normal dyeing after treatment. This subsequent immersion in aqueous media may cause hydrolysis of the reaction product of the keratin fibers with the isocyanate/ monomeric polyfunctional compound system, but whatever the reason, sutficient improvement is noted that a scouring or equivalent operation or other mechanical working of the fabric after curing is a highly preferred technique.

Improved shrinkage control is obtained in many instances if an aging period is interposed between the curing and scouring operations. Aging is similarly preferred in the durable setting of keratin fibers, although the scouring operation, for a garment manufacturer, is generally not feasible or necessary in this particular embodiment of the invention. This aging, believed to be an extenuation of the curing mechanism, may be conducted for any desired period of time based upon degree of shrinkage inhibition obtained. Aging periods of from about 12 to about 24 hours, or more or less are quite satisfactory.

While any amount of the various systems of this invention may be applied to structures containing keratin fibers to modify the characteristics thereof, excellent relaxation and felting shrinkage inhibition and/or settability has been obtained at levels as low as about 2% total pickup of all components added. If it is desired to obtain relaxation shrinkage inhibition only or a lesser degree of settability then lesser amounts may be used. Generally, no more than about 6% by weight of the component is required in any instance. Greater amounts, e.g., up to about or more may be utilized, if desired, for specific end uses where stiffer fabrics are desired.

The desired amount of the components may be applied by any of the conventional techniques for applying liquids to fabrics, for example, by padding, immersing, spraying, from applicator rolls or other techniques whereby all fibers are treated substantially uniformly.

It has been found that better results are obtained if the pH of the fabric or treating solution is maintained substantially neutral. Strongly basic solutions, for example, those above a pH of about nine, may cause excessive damage to keratin fibers if the pH thereof is raised to this level for too long a period of time, while some difficulty may be experienced in obtaining good results when the fabric or treating solution is maintained below a pH of about three. The fabric or other structure, which is often quite acidic, because of the carbonizing procedure which entails treatment with strong acid, is preferably washed or neutralized prior to treatment in accordance with this invention, to raise the pH level thereof.

The process of this invention may be utilized to improve the properties of any structure containing keratin fibers, either woven, non-woven, or knitted, dyed or undyed. Dyeing may be conducted after these structures have been treated in accordance with this invention without deleterious effects on the dyestuffs.

[For that matter, it has been found that pre-treatment of keratin fibers with the systems of his invention greatly enhances the dyeability of such fibers with conventional dyestuffs. The keratin fibers accept the dyestuffs more readily and to a greater degree after reaction ith the systems of the invention, so that less dyestutf is required for a given shade of dyeing. For example, after treatment of keratin fibers in accordance with this invention, up to 10 20% less dyestutf is required to obtain the same shade when dyeing these keratin fibers with premetallized and acid milling dyestuffs used conventionally to dye keratin fibers, particularly wool.

The structure may be composed entirely of wool fibers or be produced from blends thereof with synthetic, natural or other keratin fibers. Preferred synthetic fibers include polyamides, such as poly(hexamethylene adipamide) and those derived from caprolactam; polyesters, such as poly(ethylene terephthalate); and acrylic fibers, such as acrylonitrile homopolymers or 'copolymers containing at least about combined acrylonitrile, e.g., acrylonitrile/methylacrylate (85/15) and cellulosics, such as cellulose acetate and viscose rayon. Of the natural fibers which may be blended with the keratin fibers, cotton is preferred. Other keratin fibers include mohair, alpaca, cashmere, vicuna, guanaco, camel hair, silk, llama, and the like.

Among the suitable isocyanates that may be used in accordance with this invention there are included aryldiisocyanates, such as toluylene-ZAdiisocyanate, toluylene-2,6-diisocyanate, 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, 1,5-naphthylene diisocyanate, m-phenylene diisocyanate, diphenyl-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate, diphenylsulphone-4,4'-diisocyanate, 1-isopropylbenzene-3,S-diisocyanate, l-methyl-phenylene-2,4-diisocyanate, naphthylene-1,4-diisocyanate, diphenyl-4,4-diisothiocyanate and diisocyanate, benzene- 1,2,4-triisothiocyanate, 5-nitro-1,3-phenylene diisocyanate, xylylene-l,4-diisocyanate, xylylene-1,3-diisocyanate, 4,4- diphenylenemethane diisocyanate, 4,4'-dipheny1enepropane diisocyanate and xylylene-l,4-diisothiocyanate and the like; alicyclic diisocyanates, such as dicyclohexamethane-4,4-diisocyanate and the like; alkylene diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate and the like, as well as mixtures thereof and including the equivalent isothiocyanates. Of these compounds, the aryldiisocyanates are preferred because of their solubility and availability.

Additional isocyanates include polymethylene diisocyanates and diisothiocyanates, such as ethylene diisocyanate, dimethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, and the corresponding diisothiocyanates; alkylene diisocyanates and diisothiocyanates such as propylene-1,2-diisocyanate, a, 3- dimethyltetramethylene diisocyanate and diisothiocyanate, butylene-l ,2-diisocyanate, butylene-1,3 -diisothiocyanate, and butylene-1,3-diisocyanate; alkylidene diisocyanates and diisothiocyanates such as ethylidene diisocyanate (CH CH( NCO) and heptylidene diisothiocyanate (CH (CH CH (CNS) cycloalkylene diisocyanates and diisothiocyanates such as 1,4-diisocyanatocyclohexane, cyclopentylene-1,3-diisocyanate, and cyclohexylene- 1,2-diisothiocyanate, aromatic polyisocyanates and polyisothiocyanates such as aliphatic-aromatic diisocyanates and diisothiocyanates such as phenylethylene diisocyanate (C H CH(NCO)CH NCO); diisocyanates and diisothiocyanates containing heteroatoms such as SCNCH O'CH NSC, SCNOH CH OCH CH NSC and SCN(CH -S(CH NSC; 1,2,3,4-tetraisocyanatobutane, butane-1,2,2-triisocyanate, toluylene-2,4,6-triisocyanate, toluylene-2,3,4-triisocyanate, benzene-1,3,5-triisocyanate, benzene-1,2,3-triisocyanate, 1-isocyanato-4- isothiocyanatohexane, and Z-chloro-1,3-diisocyanatopropane.

The preferred diisocyanates, diisothiocyanates and mixed isocyanate-isothiocyanates have the general formula ZON-*RlNCZ in which R is a divalent hydrocarbon radical, preferably aryl, and Z is a chalcogen of atomic weight less than 33. For availability, toluylene-2,4-diisocyanate is preferred.

The isocyanates utilized in accordance with this invention may be derived from a blocked isocyanate to produce essentially the same effect. Blocked isocyanates contain little or no free isocyanate groups, as the result of the addition onto these groups by active hydrogen compounds (as determined by the Zerewitinoff method). These addition products are relatively inert at room temperatures, but have only limited thermal stability so that, upon heating beyond a certain temperature, called the unblocking temperature, the addition product is activated, or freed, to form the same type product with keratin fibers as would the unblocked compound.

Preferred adduct-forming compounds produce adducts which may be activated, or unblocked, by heat alone. Typical active hydrogen compounds which provide heatreversible adducts include the following:

(1) Tertiary alcohols, such as tertiary butyl alcohol, tertiary amyl alcohol, dimethyl ethinyl carbinol, dimethyl phenyl carbinol, methyl diphenyl carbinol, triphenyl carbinol, l-nitro tertiary butyl carbinol, l-chloro tertiary butyl carbinol, and triphenyl silinol and the like;

(2) Secondary aromatic amines which contain only one group having a hydrogen reactive with an isocyanate group, such as the diaryl compounds, including diphenyl amine, o-ditolyl amine, m-ditolyl amine, p-ditolyl amine, N-phenyl toluidine, N-phenyl xylidine, phenyl alpha naphthyl amine, phenyl beta naphthyl amine, carbazole, and the nuclear substituted aromatic compounds such as 2,2'-dinitro diphenyl amine and 2,2-dichloro diphenyl amine and the like;

(3) Mercaptans, such as 2-mercaptobenzothiazole, 2- mercapto thiazoline, dodecyl mercaptan, ethyl Z-mercapto thiazole, dimethyl 2-mercapto thiazole, beta naphthyl mercaptan, alpha naphthyl mercaptan, phenyl Z-mercapto thiazole, 2-mercapto-5-chloro-benzothiazole, methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, and ethinyl dimethyl thiocarbinol and the like;

(4) Lactams, such as epsilon-caprolactam, delta-valerolactam, gamma-butyrolactam, and beta-propiolactam;

(5) Imides, such as carbimide, succinimide, phthalimide, naphthalimide, and glutarimide;

(6) Monohydric phenols in which the hydroxyl group is the only group containing hydrogen reactive with the isocyanate group, such as the phenols, cresols, xylenols, trimethyl phenols, ethyl phenols, propyl phenols, chloro phenols, nitro phenols, thymols, carvacrols, mono alpha phenyl ethyl phenol, di alpha phenyl ethyl phenol, tri alpha phenyl ethyl phenol, and tertiary butyl phenol and the like;

(7) Compounds containing enolizable hydrogen, such as acetoacetic esters, diethyl malonate, ethyl n-butyl malonate, ethyl benzyl malonate, acetyl acetone, acetonyl acetone, benzimidazole, and 1-phenyl-3 methyl 5-pyrazolone and the like.

The adduct-forming compounds should, of course, possess only one group containing a reactive hydrogen atom. The presence of more than one such group would permit polymerization reactions with the polyisocyanate, which are not desired in most instances.

Among the more preferable adduct-forming compounds are included diphenyl amine, phenyl beta naphthylamine, succinimide, phthalimide, tertiary butyl alcohol, tertiary amy alcohol, dimethyl ethinyl carbinol, acetoacetic ester, diethyl malonate, mono alpha-phenyl ethyl phenol, epsilon-caprolactam, and 2- mercaptobenzo-thiazole and and others shown in the examples.

It is believed that the adducts formed by reacting a polyisocyanate or prepolymer therefrom with a compound from the groups listed above will become activated and dissociate into the original components upon application of heat to the system, so that such adducts may be mixed with reactants having a plurality of groups containing reactive hydrogen with the result that there is a reduction in the rate of reaction forming the polymeric materials until the mixture is subjected to heat.

In the preparation of the mono-adducts in general, the polyisocyanate and the adduct-forming compound are usually dissolved in a suitable inert solvent such as toluene, methyl ethyl ketone, or o-dichlorobenzene. The solutions are stirred together and permitted to stand. The reaction should be caused to take place at a temperature below the decomposition temperature of the desired product and preferably at a temperature not exceeding approximately C. In most instances, the reaction will proceed satisfactorily at room temperature when the solvent used for the isocyanate compound and blocking agent is not also a solvent for the adduct formed, the adduct formed separates from the solution and is removed therefrom by filtration or evaporation of the solvent. The time required for the adduct to form will vary from a few minutes to several hours depending upon the particular reactants used. If a mono-adduct of a polyisocyanate is desired, usually an excess of the polyisocyanate is provided so that the product which separates will be substantially pure mono-adduct. The precipitated product will probably contain small amounts of unreacted material which, if necessary, can be removed by recrystallization or extraction procedures known to those skilled in the art.

In one embodiment of this invention, a blocked isocyanate is applied to keratin fibers in combination with the desired monomeric compound. Upon heating beyond the unblocking temperature, e.g., during curing, the blocked isocyanate is believed to dissociate into the corresponding isocyanate and blocking agent, the isocyanate then being free to react with the monomeric compound and keratin fibers in the presence of the blocking agent. The mechanism of this particular reaction is no more fully understood than the reaction using unblocked isocyanates, but the result is essentially the same whether the isocyanate is blocked or unblocked, indicating that the reaction mechanism for the respective reactions, whatever they are, are essentially similar.

When a blocked isocyanate compound is utilized, the ratio of--N=%X groups to active hydrogen atoms is computed from the number of N=C=X groups theoretically available after unblocking.

Catalysts can be utilized in this embodiment of the invention just as if the isocyanate compound were not blocked.

Since these blocked isocyanate compounds are not free to react with other reactants or the keratin fibers except upon thermal activation, they are quite stable, so that the use of a non-reactive organic solvent is not necessary. Consequently, the blocked isocyanate compounds may be applied to keratin fibers from aqueous systems, e.g., in the form of an aqueous emulsion or dispersion. For better penetration and uniformity of application of the blocked isocyanate compound into the keratin fibers, however, it is still preferred to apply these compounds from an organic solution.

The blocked isocyanate compounds are stable during storage and would be preferred in some instances where stability is a problem. It should be noted, however, that the use of non-reactive solvents substantially eliminates stability problems with the unblocked isocyanates utilized herein, so that these systems are generally preferred for the improved results obtained in their use.

As noted above, keratin fibers can be durably set in any given configuration by applying one of the above isocyanate compounds and a polyfunctional monomeric compound to the fibers and curing while holding the fibers in the desired configuration. The keratin fibers, particularly fabrics containing them, are most conveniently held in the desired configuration at least during the initial stages of curing by pressing elements, preferably heated to initiate and facilitate curing. For example, there may be utilized such pressing elements as hand irons, pleating papers, rotary presses, decating machines, paper-presses, calender rolls, Hoffman presses, and the like.

It is also possible, in accordance with this invention, to set crimp in keratin fibers either in fabric form or prefabric form, e.g., roving, sliver, yarn and the like.

In pre-fabric form, the fibers can be set by curing while maintaining the fibers in a crimped or otherwise distorted configuration. The distorted configuration is most readily achieved in this embodiment of the invention by mechanical means, such as gear crimping apparatus, stufier boxes and the like.

One of the systems of this invention can be applied to the fibers prior to distortion thereof, or afterwards, as desired, although it is generally preferred for control purposes to impregnate the fibers with one of the systems of this invention prior to distortion.

Permanently crimped yarn can also be obtained by knitting the yarn into fabric form and setting the fabric by impregnating the fabric with one of the systems of this invention and curing. The cured, and thereby set,

knitted fabric is then unravelled. The resulting yarn is permanently set in the configuration in which it was set while in knitted form.

The setting of crimp in keratin fibers in fabric form has its greatest applicability in the field of stretch fabrics. In the production of all-wool stretch fabrics, or fabrics containing at least a major proportion of wool fibers, a base fabric is shrunk by immersion in a treating solution, with or without reducing agents, so as to increase the crimp amplitude in either or both warp and filling yarns thereof. This increased crimp amplitude is substantially recoverable as stretch in the fabric. When such a fabric is treated with one of the systems of this invention and cured while in its shrunken condition, the rate of the fabrics return from a stretched condition, i.e., the fabrics elastic recovery rate, is greatly increased, thereby providing a livelier stretch fabric.

Once again, one of the systems of this invention may be applied to the fabric before or after shrinking, but, in this embodiment, it is generally preferred to impregnate the fabric with one of the systems of this invention after shrinking in order to avoid any effects that the shrinking bath may have on the compound systems of this in vention. The impregnated fabric is then dried and cured to set the fabric in its shrunken condition.

Crimp in the yarns of a fabric may also be induced by mechanical means, such as compacting wherein a fabric is mechanically shrunken in a given direction, e.g., the warp direction. One apparatus for accomplishing this effect is the Compactor, trade name for equipment developed by Fabric Research Laboratories. In this embodiment of the invention, the fabric is preferably impregnated with one of the compound systems, dried, compacted, and cured to permanently set the fabric in its compacted form to obtain stretch in the direction of compacting. This technique is particularly useful for obtaining fabrics having stretch in the warp direction.

Fabrics having enhanced stretch in the filling direction only can be obtained by impregnating the fabric with one of the systems of this invention and exerting tension forces thereon in the Warp direction during either or both drying and heating wherein curing it initiated. By this procedure, the crimp amplitude in the filling yarns is increased. The fabric is maintained in this condition throughout drying and curing, which as noted above, generally extends through an aging period to provide a fabric having enhanced stretch properties in the filling direction.

Fabrics treated with the various systems of this invention can have durable configurations imparted thereto in the textile mill, e.g., by pressing to impart a durable, lustrous finish, or presensitized in the mill for subsequent durable setting by the garment manufacturer.

Durable luster or other effects wherein surface fibers of the fabric are set in a given configuration, can be imparted to fabrics in the mill by impregnating the fabric with the systems of this invention, and then at least partially curing the impregnated fabric while pressing at least one surface, e.g., by passing the impregnated fabric between heated rolls at a temperature sufiicient to initiate the cure. For embossed effects, batch or continuous molding procedures involving longer curing times under pressure are preferred.

Alternatively, the impregnated fabric can be pressed into the desired configuration and, in a separate operation, cured while substantially maintaining the configuration, whereupon this configuration will be retained even during subsequent wetting. In other Words, it is essential only that the fabric he maintained in the desired configuration during curing. The configuration is most conveniently imparted during the early stages of curing, but the curing step can follow the pressing step if desired. In many instances, in fact, curing continues during an aging period following the normal curing operations. In that event, improved results are obtained if care is taken to maintain the fabric in its desired configuration during aging also. For that matter, some permanent setting of the fabric can be achieved during the aging period if desired.

Calendering techniques are preferred for imparting finishes in the mill. Calendering pressures from about /2 ton to about 2 tons per linear inch, preferably from about 1 ton to about 1 /2 tons per linear inch, are preferred. The upper limit for calendering pressures may be higher; the only real limitation being the equipment utilized and the properties desired.

Fabrics may be presensitized in the mill for subsequent durable setting by garment manufacturers by impregnating the fabric with one of the systems of this invention and maintaining the dried impregnated fabric in a substantially uncured state until after garments have been produced from the fabric. The fabric can then be pressed into the desired configuration and cured, whereupon the configuration is durably set into the fabric.

As when lustrous finishes or other configurations are imparted at the mill level, the pressing and curing operations, though preferably simultaneous, may be performed in sequence, provided the fabric is maintained in the desired configuration, e.g., in a creased state, during curing. For example, an impermanent crease can be imparted to the fabric on the conventional Hoffman press utilized by the majority of garment manufacturers, particularly trouser manufacturers, and the creased fabric aged in this configuration to permanently set the crease.

In the presensitizing field, it is preferred to use blocked polyfunctional isocyanate, since the blocked compounds have greater stability during shipment and storage than the equivalent unblocked compound. Storage periods for presensitized fabrics vary considerably, so that the blocked compounds provide a margin of safety without affecting performance.

In this embodiment of the invention, the blocked compound on the fabric is activated for reaction with the keratin fibers and other active hydrogen compounds available on the fabric by means of a heat-setting operation, e.g., by Hoffman-pressing, steaming in an autoclave and the like, during which curing is at least initiated. Curing can then be completed during an aging period. For best results the fabric is maintained in the desired configuration during aging or at least until curing has been substantially completed.

A further advantage of this embodiment is that the blocked systems of this invention can be applied to the fabric from a water-based system, such as a dispersion or emulsion. Emulsions of these systems are normally produced from organic solutions of the blocked isocyanate compound by the addition of water and well known emulsifying agents thereto. This procedure, obviously, is less costly than when organic solutions per se are utilized, although improved penetration and hand is obtained when the blocked compound is applied to the keratin fibers from an organic solution.

As in the other embodiments of this invention, improved results are generally obtained when a catalyst and/or coreactant are present during curing. The same amounts of reactants are utilized for durable setting in a given configuration as are utilized for stabilization of fabrics.

Durable configurations are imparted, in accordance with this invention, to fabrics containing keratin fibers while obtaining many desirable properties in the fabric. For example, the fabric is substantially stabilized toward both relaxation and felting shrinkage and, furthermore, has enhanced physical properties, such as tensile strength and abrasion resistance, rather than diminished physical properties as results from the prior art processes which utilize reducing agents. In addition, fabrics so treated have no unpleasant odor such as characterizes the products of these other processes. Furthermore, these durable configurations are obtained in the absence of the large quantities of water required by many prior art processes.

Stabilization and/or setting of a fabric depends to a great extent on its density, e.g., at lower densities, higher levels of treatment are usually utilized for best results.

The process of this invention may be varied to provide various levels of control of both relaxation and felting shrinkage and settability. For example, in some fabrics it may be desired to reduce relaxation shrinkage only, in that washability by reduction of felting shrinkage may not be required. For washable fabrics, both relaxation and felting shrinkage should be reduced to an acceptable level. Techniques for providing both type effects are illustrated in the following examples.

In many of the following examples, particularly where the level of shrinkage is above about the shrinkage values obtained may be lowered even further merely by increasing the level of pickup of the components. In the examples, the effect of varying certain of the components is shown by lowering the level of pickup, so that differences in effect will be more apparent.

Parts are given on a dry basis in the examples, as percent pickup on the wool sample being treated, unless otherwise indicated.

In preparing the solutions of the following examples, the monomeric compound is first diluted below about 20% in trichloroethylene. The polyfunctional isocyanate, blocked or unblocked, is also diluted to this level and the solutions are then mixed and catalyst is added to provide the desired proportion of the various components. The resulting solution is diluted further with trichloroethylene, depending upon the wet pickup obtained on application of the various solutions to the fabric to obtain the desired amount of pickup (on a dry basis).

EXAMPLE I Various solutions in trichloroethylene, containing varying amounts of toluylene-2, 4-diisocyanate, N-methyl morpholine catalyst and Quadrol [trade name for N,N,N', N, tetrakis(dihydroxy propyl) ethylene diamine] are adjusted by dilution with trichloroethylene to reduce the percent solids content so that at a wet pickup of 145% on the fabric using a laboratory pad roll, pickups as indicated in Table I are obtained. The fabric used in all examples is a plain weave, all-wool piece-dyed fabric having 35 ends and 24 picks per inch of 3.875 run yarn made on the woolen system. Swatches of this fabric are impregnated with the compound solutions, dried for 5 minutes at 160 F. and cured for minutes at 250 F. The swatches are aged at room conditions for 48 hours before testing for relaxation and felting shrinkage.

Shrinkage values are determined by immersing the swatches in water containing 0.1% of Surfonic N-95 (a non-ionic wetting agent), at 140 F. for 30 minutes, after which they are dried in a relaxed state on racks, pressed, and measured to determine the extent of relaxation shrinkage. The swatches (3 lbs. load) are then washed in a Kenmore washer at 140 F. for 12 minutes, rinsed at 105 F. and spun-dried for a total cycle of minutes. The wash cycle is repeated 9 times, after which felting shrinkages are measured, These values are given in Table I.

Shrinkage tests in all subsequent examples are run as described herein.

TABLE I Area shrinkage Pickup (percent) dry basis (percent) Diisoeyanate Quadrol Catalyst Relaxation Felting 1 Control.

EXAMPLE II Following the procedure of Example I, a swatch of the fabric of Example I is impregnated with a trichloroethylene solution containing polyphenylethylene diisocyanate, catalyst and Quadrol to a pickup of 4.5% diisocyanate, 0.55% Quadrol, and 0.45% catalyst. After drying, curing and aging as in Example I, the relaxation and felting shrinkage values, respectively, are 3.6 and 2.0%.

EXAMPLE III Into 82.4 parts of trichloroethylene are added 1.4 parts of 1,4-butanediol and 10 parts of toluylene-2,4-diisocyanate. The resulting mixture separates into two layers, so 4.2 parts of ethanol are added. After stirring, a clear uniform solution is obtained and 1.0 part of N-methyl morpholine is added. A swatch of the fabric of Example I is padded to a pickup on the fabric (dry basis) of 10.0% toluylene-2,4-diisocyanate, 1.4% of 1,4-butanediol and 1.0% catalyst. After drying, curing, and aging as in Example I, relaxation and felting shrinkage values of 5.1 and -0.1%, respectively, are obtained.

This procedure is repeated on fabric which has been dried at 250 F. for 15 minutes, removed to a desiccator and allowed to cool, after which it is removed and immediately padded with the solution. Relaxation and felting shrinkage values obtained on this fabric are 5.9 and 2.2%, respectively.

EXAMPLE IV A swatch of the wool fabric of Example 1 is impregnated with a trichloroethylene solution containing toluylene-2,4-diisocyanate, methyl diethanolamine, and N-methyl morpholine catalyst to a pickup of 10% diisocyanate, 1.8% methyl diethanolamine, and 1% catalyst. After drying, curing, and aging as in Example I, shrinkage values of 3.3% relaxation and 9.4% felting, respectively, are obtained. This procedure is repeated on a fabric pre-dn'ed as in Example III to obtain relaxation and felting shrinkage values of 5.3 and 3.3%, respectively.

This procedure is repeated except that 1% stannous octoate is also added to the fabric. Relaxation and felting shrinkage for the fabric containing regain levels of moisture are 2.4 and 5.1%, respectively. The pre-dried fabric relaxation and felting shrinkage values, respectively, are 2.6 and 2.8%.

EXAMPLE V Into 4.2 parts of ethanol are dissolved 1.4 parts of trimethylol propane. The resulting solution is then added to 82.4 parts of trichloroethylene containing 10.0 parts of toluylene-2,4-diisocyanate. Into the resulting solution is added 1.0 part of N-methyl morpholine, after which the solution is padded onto a swatch of the fabric of Example I to pickup levels of 10.0% toluylene-2,4-diisocyanate, 1.4% trimethylol propane and 1.0% catalyst. After drying, curing, and aging as in Example I, relaxation and felting shrinkage values 4.4 and 1.2%, respectively, are obtained.

This procedure is repeated on a fabric pre-dried as in Example III to obtain relaxation and felting shrinkage values of 7.0 and 0.8% respectively.

EXAMPLE VI The woolen fabric of Example I is padded with an aqueous solution containing 11.0 parts of pentaerythritol, after which the fabric is dried and padded through trichloroethylene containing 100 parts of toluylene-2,4-diisocyanate and parts of N-methyl morpholine catalyst to obtain pickups of 10% diisocyanate, 1.1% pentaerythritol and 1% catalyst. The fabric is then dried and cured as in Example I. After aging for 24 hours, a relaxation shrinkage value of 3.1% is obtained.

EXAMPLE VII A swatch of the fabric of Example I is padded with a trichloroethylene solution containing toluylene-2,4-diisocyanate, triethanolamine and N-methyl morpholine catalyst to a pickup on the fabric of 10% diisocyanate, 1.6% triethanolamine and 1% catalyst. Relaxation and felting shrinkage values for a fabric containing regain levels of moisture at the time of padding are 3.2 and 2.0%, respectively, while a fabric pre-dried prior to padding has relaxation and felting shrinkage values of 6.4 and 1.3%, respectively.

EXAMPLE VIII Following the procedure of Example I, a trichloroethylene solution containing toluylene-2,4-diisocyanate, pimelic acid and N-methyl morpholine catalyst is padded onto a swatch of the fabric of Example I to provide a pickup on the fabric of 3.8% diisocyanate, 1.2% pimelic acid and 0.4% catalyst. After drying, curing and aging as in Example I relaxation and felting shrinkage values 18 EXAMPLE XI The procedure of Example VIII is repeated except that ethylene thioglycol is substituted for pimelic acid and the pickup on the fabric is 4.25% diisocyanate, 0.75% ethylene thioglycol and 0.4% catalyst. Similar results are again obtained.

Substantially similar results are obtained when this procedure is repeated except that butanedithiol is substituted for ethylene thioglycol and the pickup on the fabric is 4.1% diisocyanate, 0.9% butanedithiol and 0.4% catalyst.

EXAMPLE XII The results obtained in Example VIII are improved when 0.4% stannous octoate is added to the fabric in combination with the other components.

EXAMPLE XIII A mixture of diisocyanate isomers containing 80% toluylene-2,4-diisocyanate and 20% toluylene-2,6-diisocyanate are blocked by the addition thereto, in stoichiometric amounts, of the various active hydrogen compounds dissolved in the various solvents containing certain catalysts as set forth in Table II.

After the heat of reaction subsides, the resulting solutions are heated at 80 C. for 3 hours. The resulting hot solutions are diluted to 10% solids with additional solvent heated to the same temperature, after which 10% trichloroethylene solutions of Quadrol containing N-methyl morpholine are added thereto. The resulting systems are diluted further with l/ 1 solutions of trichloroethylene and the particular solvent used for blocking, so that at 135% Wet pickup during padding onto samples of the allwool fabric of Example I, the following pickups on a dry basis, are obtained: 0.55% Quadrol, 0.2% N-methyl morpholine and sufiicient blocked diisocyanate compound to provide 2.0% of active diisocyanate.

The impregnated fabric is then dried and cured at the temperatures given in Table II.

In each instance, the relaxation and felting shrinkage are found to be similarly reduced. of the fabric samples are greatly inhibited.

TABLE II Curing tempera- Bloeking agent Solvent Catalyst tnre, C.

Ethanol 160 a 150 95 Toluene. 85 Chloroform 65 Guaiacol do 100 Resorcinol Dioxane 90 PhloroglueinoL. .do 120 l-Dodeeanethiol oluene do 120 Benzenethiol Chloroiorm Triethylenediamine 100 Ethyl acetoacetate Toluene Sodium methoxide 100 Diethyl malonate do o 95 e-Caprolactam do Triethylenedlamin 150 Ethyl carbamate Carbontetrachlorid Triethylamine 135 Boric acid Tetrahydrofuran None 85 EXAMPLE 1X The procedure of Example VIII is repeated except that phthalic acid is substituted for pimelic acid and the pickup on the fabric is 7.6% diisocyanate, 2.4% phthalic acid and 0.8% catalyst. Once again, fabric properties such as abrasion resistance and tensile strength are improved, while the relaxation and felting shrinkages are substantially reduced.

Substantially similar results are obtained when these active hydrogen compounds are utilized to block the isocyanates of Example H and this blocked isocyanate is applied to the fabric and cured under the same conditions.

Furthermore, similar results are obtained when 1.4%

of 1,4-butanediol, 1.8% methyl diethanolamine, 1.4% trimethylol propane, 1.1% pentaerythritol, 1.6% triethanolamine, 1.2% pimelic acid, 1.4% azeleic acid, 1.2% pimelic acid, 2.4% phthalic acid and 0.75 ethylene thioglycol are substituted for Quadrol, although the hand of the Quadrol-treated fabrics is slightly superior to the other samples.

EXAMPLE XIV The systems of Example XIII produce substantially similar results when applied from an aqueous emulsion, although the fabrics so-treated have slightly harsher handle.

Dry crease performance data are obtained in the following examples from presensitized fabric samples having dimensions of 4% inches in the filling direction by 6 inches in the warp direction. These samples are folded in half with the fold parallel to the warp yarns. The samples are then placed on a Hoffman press, the cover is closed and locked and the samples are pressed for the periods of time indicated in the example, generally with 30 seconds top steam. 30 seconds baking followed by 10 seconds vacuuming.

The creased samples are aged 18 hours, then opened and placed in a standing water bath which contains a wetting agent and is heated to 170 F. After 30 minutes the samples are removed, folded along their original crease line and allowed to air dry. After drying, the creases remaining in the samples are rated subjectively by at least three observers, the crease ratings running from 1 (no appreciable crease) to (very sharp crease).

EXAMPLE XV Into 858.63 grams of trichloroethylene are dissolved 8.9 grams toluylene-2,4-diisocyanate, 3.27 grams Quadrol and 0.20 gram Dow Cornings silicon resin 1172. The resulting solution is padded onto a sample of Deering Milliken woolen fabric style No. 477 to 145% Wet pickup. After drying for 5 minutes at 160 F., the fabric is folded and creased on a Hoffman press using a pressing cycle of 30 seconds steam, 30 seconds bake followed by seconds of vacuum. The creased fabric is removed and, while maintained in a creased configuration, is cured for 5 minutes at 260 F. After aging overnight, the fabric is tested as set forth above. The crease rating of this fabric is 5.0, the highest possible rating.

EXAMPLE XVI A sample of the fabric of Example XV is creased on a Hoffman press as set forth in Example XV. The fabric, while still creased, is padded to 145% wet pickup with the solution of Example XV, dried for 5 minutes at 160 F. and cured for 5 minutes at 250 F. All operations are conducted while maintaining the fabric in its creased condition.

After aging overnight and testing as set forth above, the crease rating is 5.0, the highest possible rating.

EXAMPLE XVII An all-wool flannel fabric is padded with a trichloroethylene solution containing toluylene-2,4-diisocyanate, Quadrol and silicone resin 1172 to provide a pickup of 2.0%, 0.25% and 0.2% of these components, respectively. The fabric is then dried by heating for 5 minutes at 160 F., after which it is folded and pressed on a Hoffman press under a cycle of 30 seconds steam, 30 seconds bake, followed by 10 seconds vacuum. The fabric is then tested for crease retention after minutes and after aging overnight. The crease rating of both samples is excellent, the crease rating of the sample which was aged overnight being slightly higher.

Both crease ratings are increased slightly when the fabrics are baked for 3 minutes on the Hoffman press. The best crease ratings are obtained when the samples are heated for 15 minutes at 250 F. after Hoffman pressing, the crease rating being still higher after aging overnight, although the increase in rating after aging overnight is not as marked as when no subsequent heat step is used.

EXAMPLE XVIII Various fabric swatches are padded as in Example XVII to the same level of pickup of the various components. All swatches are dried for 5 minutes at 160 F., after which one swatch is creased as in Example XVII on a cycle of 30 seconds steam, 30 seconds bake and 10 seconds vacuum. After creasing, the swatch is heated for 10 minutes at 250 F.

The remaining samples are similarly heated for 10 minutes at 250 F. and are not creased as above until after a time lag of 15 minutes, 1, 3, 6 and 18 hours, respectively.

The fabric sample which is creased and then heat-cured exhibits excellent crease retention properties. The remaining samples exhibit decreasingly sharp creases. For example, the fabric swatch which is creased after a time lag of 15 minutes is characterized by a good crease rating. After a time lag of 6 hours, good crease ratings still are obtained. After an 18 hour time lag, however, a crease rating of 1.0 or no crease, is obtained.

EXAMPLE XIX Substantially durable creases are obtained when allwool fabric samples are treated in accordance with each of Examples I through XVI, but creased and cured as in Example XV, the best results in crease retention being obtained in those fabric samples wherein both relaxation and felting shrinkage values are low. In the procedure of Example XIII, the creases imparted to the fabric are substantially durable after creasing on the Hoffman press for those embodiments wherein the blocking agent comprises m-cresol, o-nitrophenol, o-chlorophenol, benzenethiol, ethyl acetoacetate, guaiacol, resorcinol, boric acid and diethyl malonate. Improved results are obtained, however, when the fabric is subjected to the heating operation at 250 F. for 5 minutes, since this temperature exceeds the unblocking temperature for these compounds and assures release of active isocyanate groups. For the blocked compounds that are activated at higher temperatures, e.g., wherein the blocking agent comprises ethanol, 2-methyl- 2-propanol, phloroglucinol, l-dodecanethiol, benzenethiol, ethyl acetoacetate, epsilon-caprolactam, and ethyl carbamate, the heating operation is conducted at the unblocking temperature shown in Table II for the individual compounds.

EXAMPLE XX An all-wool fabric is impregnated with the solution of Example XV to the same level of pickup. After drying at 160 F., the fabric is pressed by passing through a three roll calender having a fiber-filled roll set between two steel rolls in a vertical arrangement. The fiber-filled roll is a 55/45, corn husk/ cotton filled roll. Temperatures of about 350 F. and pressures of about tons, which correspond to 3200 lbs. per linear inch at the nip, are employed. The fabric is then full-decated by forcing steam through the fabric at 60 psig. and holding for 10 minutes after breakthrough. The fabric so treated is found to have a high luster which is durable to steam sponging and wetting.

As noted above, the reactive components may all be applied to the fabric from a single solution, as by padding, spraying or the like, in a continuous process characterized by high levels of production. For example, since the fabric need be contacted with the solution for only so long a time as is necessary to impregnate the fabric, and this is very brief in that the organic solutions readily penetrate wool fabrics, production rates of 60 yards per minute or more with conventional padding equipment are entirely feasible.

The process of this invention may be utilized to inhibit the relaxation shrinkage of any wool fabric, including those fabrics which have been stretched and dried in stretched configuration to obtain increased yardage. Normally the increased yardage obtained in this manner is lost during any subsequent wetting, such as during treatment to reduce shrinkage by the prior art processes, or during sponging which is necessary on fabrics treated by conventional techniques to remove relaxation shrinkage from the fabric. The increased yardage obtained by stretching and drying in stretched configuration, however, is retained after treatment of these fabrics in accordance with this invention, because essentially no relaxation shrinkage occurs during treatment, as occurs in previous techniques involving water immersion. The resulting fabric, furthermore, remains resistant to relaxa- 21 tion shrinkage at later stages in its use, so that fabrics treated in accordance with this invention may be dyed, scoured or otherwise processed with no appreciable yardage loss as would occur when stretched fabrics treated by prior art processes are subjected to the same subsequent treatments. In addition, fabrics treated by the process of this invention may be delivered to the consumer ready for cutting into garments, without the necessity of sponging to stabilize the fabric dimensions.

All the above advantages and many others will become apparent to those practising this invention.

That which'is claimed is: 1. A process for shrink-proofing a textile fabric containing keratin fibers comprising (a) impregnating said fabric with a non-reactive organic solvent solution containing (i) a monomeric polyisocyanate and (ii) a monomeric polyfunctional compound selected from the class consisting of polyhydroxy compounds, polybasic carboxylic acids, aliphatic polythiols and mixtures thereof; and i (b) curing said fabric at a temperature sufiicient to effect areaction between the keratin fibers and the components of the organic solution. 2. The process of claim 1 wherein the solution also contains a catalyst.

3. The process of claim 1 wherein the isocyanate is an aryl diisocyanate.

4. A process for shrink-proofing a textile fabric containing keratin fibers comprising (a) impregnating said fabric with an aqueous composition comprising (i) a monomeric polyisocyanate blocked through reaction with an organic compound having an active hydrogen atom which is activated by heating at an elevated temperature, and (ii) a monomeric polyfunctional compound selected from the class consisting of polyhydroxy compounds, polybasic carboxylic acids, aliphatic polythiols and mixtures thereof; and (b) drying and curing said fabric at a temperature suflicierit to activate the blocked isocyanate and effect a reaction between the keratin fibers and the components of the aqueous composition. 5. The process of claim 4 wherein the ratio of isocyanate groups to active hydrogen atoms in the composition is greater than one.

figuration; and

(c) heating said fabric, While maintaining it in the desired configuration, to a temperature suflicicnt to set the fabric. 7. A process for producing garments containing keratin fibers and being durably set in a desired configuration comprising 1 (a) impregnating said fibers with a non-reactive organic solvent solution containing (i) a monomeric polyisocyanate, and (ii) a monomeric polyfunctional compound selected from the class consisting of polyhydroxy compounds, polybasic carboxylic acids, aliphatic polythiols and mixtures thereof; (b) drying said fabric to remove substantially all of the liquid; (c) producing a garment from said fabric; (d) arranging said garment in the desired configuration;

and (e) curing said garment while maintaining the garment in the desired configuration. 8. The process of claim 7 wherein the isocyanate is tolylene 2,4-diisocyanate.

9. The fabric prepared by the process of claim 1.

References Cited FOREIGN PATENTS 220,077 2/1959 Australia 8128 GEORGE F. LESMES, Primary Examiner J. CANNON, Assistant Examiner US. Cl. X.R. 

